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curl: CVE-2022-43552: HTTP Proxy deny use-after-free
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From: Daniel Stenberg via curl-users <curl-users_at_lists.haxx.se>
Date: Wed, 21 Dec 2022 08:24:27 +0100 (CET)
CVE-2022-43552: HTTP Proxy deny use-after-free
==============================================
Project curl Security Advisory, December 21 2022 -
[Permalink](https://curl.se/docs/CVE-2022-43552.html)
VULNERABILITY
-------------
curl can be asked to *tunnel* virtually all protocols it supports through an
HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations using
an appropriate HTTP error response code.
When getting denied to tunnel the specific protocols SMB or TELNET, curl would
use a heap-allocated struct after it had been freed, in its transfer shutdown
code path.
We are not aware of any exploit of this flaw.
INFO
Date: Wed, 21 Dec 2022 08:24:27 +0100 (CET)
CVE-2022-43552: HTTP Proxy deny use-after-free
==============================================
Project curl Security Advisory, December 21 2022 -
[Permalink](https://curl.se/docs/CVE-2022-43552.html)
VULNERABILITY
-------------
curl can be asked to *tunnel* virtually all protocols it supports through an
HTTP proxy. HTTP proxies can (and often do) deny such tunnel operations using
an appropriate HTTP error response code.
When getting denied to tunnel the specific protocols SMB or TELNET, curl would
use a heap-allocated struct after it had been freed, in its transfer shutdown
code path.
We are not aware of any exploit of this flaw.
INFO
---- This flaw was introduced for TELNET in [commit b7eeb6e67fca68](https://github.com/curl/curl/commit/b7eeb6e67fca68) in September 7, 2006. The SMB part was introduced in 2014 with [commit aec2e865f06669](https://github.com/curl/curl/commit/aec2e865f06669). The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2022-43552 to this issue. CWE-416: Use After Free Severity: Low AFFECTED VERSIONS ----------------- - Affected versions: curl 7.16.0 to and including 7.86.0 - Not affected versions: curl < 7.16.0 and curl >= 7.86.0 libcurl is used by many applications, but not always advertised as such! THE SOLUTION ------------ A [fix for CVE-2022-43552](https://github.com/curl/curl/commit/4f20188ac644afe17) RECOMMENDATIONS -------------- A - Upgrade curl to version 7.87.0 B - Apply the patch to your local version C - Avoid using SMB and TELNET or disable HTTP proxy use TIMELINE -------- This issue was reported to the curl project on November 7, 2022. We contacted distros_at_openwall on December 12, 2022. curl 7.87.0 was released on December 21 2022, coordinated with the publication of this advisory. CREDITS ------- - Reported-by: Trail of Bits - Patched-by: Daniel Stenberg Thanks a lot! -- / daniel.haxx.se | Commercial curl support up to 24x7 is available! | Private help, bug fixes, support, ports, new features | https://curl.se/support.html -- Unsubscribe: https://lists.haxx.se/listinfo/curl-users Etiquette: https://curl.se/mail/etiquette.htmlReceived on 2022-12-21